I haven't played the game for 6 years now, but I can for sure make a list of what I know about their weaknesses
 
	Offensive weakness:
 
	lack of anti tank/structure damage output
 
	weak against air unit swarms, ex: carrier hornets, harrier squadrons, kirov parade, rocketeer, etc
 
	heavily relies on mind controlled units to attack
 
	if the mind controlling unit dies, the chaos will turn to your side instead 
 
	weak navy
 
	 
 
	Defensive weaknesses
 
	mind control units & building have a limit to how much they can take on
 
	lack of AoE damage
 
	Doesn't have much to defend with besides units.  Since only 2 defensive structures are given
 
	 
 
	Economical weaknesses
 
	bad transportation, hard to get engineers to distant tech buildings
 
	Slaves are not very reliable when enemies have anti infantry units nearby
 
	Slave miner is stationary for most of the time, easy target for missiles and also hard to run away